As has been said many times

IF you use 3rd party apps that make your applications icons to go in folders in icon view (e.g. Catorise & MyMenu or Apmefo) then IT MIGHT trigger infinite loop bug in hildon-desktop that makes hildon-desktop to take constantly couple of % of cpu. It drains battery faster than plain idle state (obviously?).

So with above prerequisites it might make your battery usage time little longer.